Power transmission means for concrete vibrator



April 27, 1965 A. wYzr-:NBEEK 3,130,625

POWER TRANSMISSION MEANSFOR CONCRETE VIBRATOR Filed July 23, 1963 (2591 5' l INVENTOIL UnitedStates Patent O 3,186,625 PWER TRANSMISSION MEANS FR CONCRETE VlBFtAIOR Andrew Wyzenheek, Chicago, Ill., assigner to Wyco Tool Co., a corporation of illinois Filed July 23, 1963, Ser. No. 296,951 4 Claims. (Cl. 259-1) This invention relates to a power transmission means for a concrete vibrator and, more particularly, to a flexible shaft for interconnecting the prime mover with the vibrator head of such a vibrator.

Although vibrators have long been used for compacting concrete, the operation has been llimited by the ability of the conventionally employed flexible shaft to deliver adequate power to the vibrator head over the required periods of time. The flexible shaft is usually arched or looped, depending upon the position of the operator, and thus develops a varying frictional resistance between the interior bearing and the rotating core. It is an object of this invention to provide a superior power connection between the motor and the vibrator head, particularly o-ne which overcomes the heretofore-tolerated limitations in operation of such a connection.

Another object of the invention is to provide a unique interior bearing made up of a spirally wound ribbon of metal wherein the ribbon is longitudinally deformed to vminimize frictional resistance.

Other objects and advantages of the invention may be seen in the details of construction and operation set down in this specification.

The invention is described in conjunction with an illustrative embodiment in the accompanying drawing, in which-- FIG. 1 is a perspective View of a vibrator embodying the invention, seen in a typical environment;

FIG. 2 is a longitudinal sectional view, on enlarged scale, of the ilexible shaft portion of FIG. 1;

FIG. 3 is a fragmentary elevational view, partially in section, of a portion of the ilexible shaft and vibrator head seen in FIG. 1; and

FIG. 4 is a transverse section through the flexible shaft as taken on the line 4 4 of FIG. 2.

Referring now to FIG. 1, the symbol O designates generally the operator of the vibrator generally designated lll. The vibrator is seen to include a head 11 in the process of being immersed in a concrete member C and which is driven in conventional fashion by a portab-le motor 12 .coupled to the vibrator head 11 by means of the flexible shaft 13. The shaft 13, as seen in FIGS. 2-4, includes an elongated core 14 terminating in a hexagon-shaped fitting 15 (designated only in FIG. 3). The core 14 is solder-connected Within a reamed portion 15a in the tting 15 so as to be slidably received within a hexagonally-shaped sleeve 16 provided as part of the vibrator head 11. The vibrator head 11 also includes the eccentrically mounted rotor 17 seen in FIG. 3. The vibrator head details can be seen in my earlier Patent No. 3,042,386.

The iiexible shaft 13 includes an outer casing 13 constructed of rubber which enoloses the core 14- and provides a mounting for a spirally wound bearing generally designated 19. The bearing 19 is seen to be longitudinally deformed along a central line to provide a rib 20 contacting the rotating core 14. Additionally, the hearing strip 19 may be folded along its edges as at 21 and 22 to develop anchoring or gripping portions which are partially embedded within the casing reinforcement 23.

The inventive bearing or liner 19 was tested using a Wyco #991-G-1O vibrator wherein a temperature CII lsensing element was located at live inches from the end of the shaft, i.e., the position designated T in FIG. 3. For purposes of comparison, an identical vibrator was employed with the exception that the ribbon providing the bearing 19 was llat instead of beaded as shown. Testing of the two vibrators was made under the extreme condition of running the head completely out of concrete.

With the beaded-type inner liner 19 shown, the :temperature rose in ten minutes from 78 to 167 F., while with the flat inner liner the temperature rose in nine minutes from 78 -to 245 F., whereupon the test had to be stopped due to failure of the shaft.

In each case, the inner liners were constructed of Phosphor bronze having an analysis of -95% copper and 5-10% tin. The tensile strength in the hard drawn oondition was 55,000 p.s.i., the Brinell hardness 88-96, and the melting-point 1661 F. The inner liner in the beaded construction shown had a thickness of 1,434, while the dat inner liner had a thickness of l/gg, both inner liners being spirally wound on a pitch of 2".

During the test, there was a noticeable difference in the run-in time of the llexible shafts. With the beaded inner liner shown, the core became seatedin the casing much faster, as a consequence of which the vibrator came up to speed quicker.

As seen in FIG. 2, which is approximately full scale, the rib 2i) upstands from the ribbon 19 about the thickness o-f the ribbon. The ribbon 19 bears lagainst the reinforcement 23, which may take the interlocked form shown.

The edge folded construction as at 21 and 22 is exaggerated in FIG. 2 and norm-ally is developed to a certain extent in the operation wherein the longitudinally-extending bead 2d is imparted to the ribbon 19.

The rib or bead 20 on the bronze ribbon is exceedingly advantageous through its stiiening of the entire ribbon, causing the ribbon to expand with greater force when placed in the :casing so as to anchor the ribbon rmly in place, minimizing any play between the ribbon liner and the ilexible core lll. In contrast to this, the ordinary flat ribbon of bronze lhas a tendency to set and contract somewhat in use, thereby bringing about an indesirable tolerance or gap. Not only is the ilat form undesirable for this purpose, but the free movement of the ribbon inner liner brings about localized areas of stress, causing premature wear and failure.

While in the foregoing speciiication a detailed description of an embodiment of the invention has been set down for the purpose of explanation, many variations in the details herein given may be made Without departing from the spirit and scope of the invention.

I claim:

1. In a vibrator for comlpacting concrete, a motor, a vibrator head, and a flexible shaft coupling said head to said motor, said shaft comprising an outer casing, a flexible core, and a spirally wound liner disposed between said core and casing, said liner comprising a strip or" relatively thin material od uniform thickness deformed centrally of its width to define a longitudinally-extending, centrally disposed rib in contacting relation with said core.

2. The structure of claim 1 in which said liner along the longuitdinal edges thereof is deformed radially outwardly into anchoring engagement with said casing.

' 3. A flexible shaft for coupling a vibrator head to a motor for compacting concrete, and the like, comprising an outer casing, a flexible core, and a spirally wound caring liner disposed between said c'ore and casing, said liner comprising a strip of relatively .thin material of uniform thickness deformed inwardly along spaced 5 longitudinal lines to deveop a centrally disposed rib contacting said core;

4. The` flexible shait of'olaim 3 in which the stripis deformed radially ouwardly along its edges into anchoring engagement with the casing.

Roeremces Ced by the Examiner UNITED ST ATES PATENTS 1,678,335 7/28 Gaston 64-2 Webb l r FOREIGN PATENTS Germany.

1,865,874 6/32 Quamstmm 711-490 1o CHARLES A.W1LLMU,TH,1 rimry Examiner. 

1. IN A VIBRATOR FOR COMPACTING CONCRETE, A MOTOR, A VIBRATOR HEAD, AND A FLEXIBLE SHAFT COUPLING SAID HEAD TO SAID MOTOR, SAID SHAFT COMPRISING AN OUTER CASING, A FLEXIBLE CORE, AND A SPIRALLY WOUND LINER DISPOSED BETWEEN SAID CORE AND CASING, SAID LINER COMPRISING A STRIP OF RELATIVELY THIN MATERIAL OF UNIFORM THICKNESS DEFORMED CENTRALLY OF ITS WIDTH TO DEFINE A LONGITUDINALLY-EXTENDING, CENTRALLY DISPOSED RIB IN CONTACTING RELATION WITH SAID CORE. 